shaft2 (shaft)

[In this sense not found in ME. or AS., and due to G. influence (from German miners in England); = Dan. skakt, it is expected that extensive operations will be carried on, the shafts are usually sunk vertically, and connected with the lode at various depths by cro -drifts or levels. When, however, the dip of the lode is pretty uniform and its thickne considerable, all the shafts of the mine may be sunk upon it as inclines. This is the case with the largest mines on Lake Superior. Shafts have various forms, some being round, others oval; but the most common shape is rectangular. In large mines the shaft is usually divided into several compartments, one being used for the pumping-machinery, two or more for hoisting ore, and another for lowering heavy timbers. In the English coalmines the shafts are mostly circular in section; in Belgium, polygonal; in the anthracite region of Pennsyl 2. In mil it. mining, a vertical pit the bottom of which serves as a point of departure for a gallery or series of galleries leading to mines or chambers filled with explosives.-3. The interior space of a blast-furnace above the hearth, and especially the part where the diameter remains nearly the same, or that which is above the boshes. More often called the body of the furnace. - Pumping-shaft, in mining, the shaft in which is placed the "pit-work," or the pumping-machinery used in raising water from the lower portions of the mine. shaft3t, n. [ME. shaft, schaft, Piers Plowman (B), xi. 387.